Lighting circuit breaker panelboard modular assembly

ABSTRACT

A circuit breaker panelboard modular assembly employs a plurality of interdependent molded plastic and metal parts to multifunctionally adapt breakers of different ratings for electrical connection within the panelboard enclosure. Anti-turn connector connects the strap terminals. Captive bolts or plug-in connections are employed to attach the breakers to the power bus. A novel concealed hinge construction is used to connect the panelboard door to the panelboard housing and the breakers are individually identified within the housing by extruded plastic circuit markers.

This is a divisional of application Ser. No. 705,454, filed Feb. 25,1985, now U.S. Pat. No. 4,631,634.

BACKGROUND OF THE INVENTION

The increased use of computers throughout the circuit breaker industryfor inventory of circuit breaker components along with the automatedassembly of the components into a finished product has correspondinglyrequired a reduction in the large variety of components used with thevarious breaker ratings to make such automation practical as well aseconomically feasible. U.S. patent application Ser. No. 678,208 entitled"Automated Q-Line Circuit Breaker" in the name of Raymond Seymour et al.describes a 120/220 volt residential-type circuit breaker designed forcompletely automated assembly. U.S. patent application Ser. No. 500,643in the names of Ronald Ciarcia et al. entitled "Circuit Breaker DesignFor High Speed Assembly" describes a 277/480 volt circuit breakerdesigned for commercial applications, which is capable of automatedassembly, in part.

The industry trend toward the use of computerized inventory and partssimplification for circuit breaker manufacture implies that tremendoussavings in time and materials can also be realized in the manufacture ofthe panelboards and load centers used to house the residential andindustrial-type breakers. In the manufacture of industrial panelboards,for example, each breaker rating and design requires a tailoredpanelboard assembly for housing and supporting the breakers. Automationof industrial panelboard manufacture has heretofore been difficult toachieve because of the large variety of components required for thevarious breaker ratings. The use of sheet metal supports with insulatingplates as well as the large variety of screws, rivets and bolts requiredto assemble the metal panelboard internal assembly has complicatedearlier attempts to automatically assemble the panelboard enclosures.

The advent of high strength insulating plastic materials such as Noryl®and Valox® which are registered trademarks of General Electric Companyfor high temperature durable thermoplastic resins, has allowed the useof molded plastic components to multifunctionally provide the necessaryinsulation between the phase conductors as well as to space and supportthe breakers on the power buses.

One purpose of this invention is to describe an industrial circuitbreaker panelboard design wherein the panelboard components are capableof use with circuit breakers over a wide range of ratings withoutrequiring a correspondingly large variety of inventoried components andparts.

Another purpose of this invention is to propose a modular concept tocircuit breaker panelboard assembly wherein the main breaker, branchbreakers, neutral support and option support structures are configuredfor interconnection independent of length requirements. Any desirednumber of breakers can then be arranged on such a module and the moduleis then connected with the remaining modules of adjustableconfiguration. This modular concept can allow for a wide range ofcustomer requirements with only minor modification of the panelboardinterior.

SUMMARY OF THE INVENTION

The invention comprises an industrial circuit breaker panelboard designwherein molded plastic components are used to support and electricallyisolate the electric power bus phase conductors and to adapt variousbreaker ratings for electrical connection with each of the power buses.The use of main and branch circuit breaker modules allows a widevariation in the number of breakers that can be arranged within thepanelboard enclosure without modifying the panelboard interior. Anintegral panelboard door assembly containing a concealed durable hingeis used to simplify the external panelboard assembly. Anti-turnelectrical connectors are used to interconnect the circuit breakers withthe incoming electrical power conductors and captive bolts are used withthe breakers to connect the breakers to the power buses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end view in partial section of the panelboard modularassembly according to the invention;

FIG. 2 is a front view of the door assembly viewed from within thepanelboard assembly according to the invention;

FIG. 3 is top perspective view in isometric projection of the internalcomponents used within the panelboard assembly of FIG. 1;

FIG. 4 is a top perspective view in isometric projection of a circuitbreaker prior to connection with the interior components depicted inFIG. 2;

FIG. 4A is a partial end section through the plane A--A of the branchstrap adapter base depicted in FIG. 4;

FIG. 5 is a top perspective view of the anti-turn connectors used forconnecting the circuit breaker depicted in FIG. 3 with the electricalpower conductors;

FIG. 6 is top perspective view of an interior mounting bracket usedwithin the panelboard assembly of the instant invention;

FIG. 7 is a top perspective view of the interior mounting bracketconnecting with the interior of the panelboard assembly of the instantinvention;

FIGS. 8A-8C are top perspective views and side sectional views of thecircuit markers used within the panelboard assembly of the instantinvention, FIG. 8B is a section through the plane 8B--8B and FIG. 8C isa section through the plane 8C--8C of the circuit markers depicted inFIG. 8A;

FIG. 9 is an enlarged top perspective view in isometric projection ofthe novel hinge arrangement used with the panelboard door assemblydepicted in FIG. 1; and

FIG. 10 is a top perspective view of an alternate embodiment of thepanelboard assembly according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The lighting circuit breaker panelboard modular assembly of theinvention is shown at 10 in FIG. 1 to consist of an enclosure bounded onboth sides by a pair of opposing sidewalls 6 and a bottom pan 8. A doorassembly 114 is arranged at the front of the assembly and consists of aface plate 11 which can be made of plastic or metal and which surroundsthe door 12. A rabbet 14 surrounds the interior of the door assembly toprovide a barrier in combination with the circuit breaker shield 48 alsomade of plastic or metal, which is positioned within the panelboardassembly by means of a pair of shield supports 17. Although not shown,the circuit breakers are arranged on top of a base 32 by means of thecircuit breaker support hooks 34 and insulators 33 integrally formedwithin the base. The base is injection molded from Noryl plastic whichwas selected for its strength and good electrical resistance properties.Electrical connection is made with the power buses 30 which are attachedto the bottom portion of the base. Each power bus carries one phase of asingle or three phase power supply. The base is supported by means of apair of side rails 26 which in turn are supported by a pan 112. A hinge15 is arranged on the interior of the face plate and door in such amanner as to be completely concealed from the exterior of the door asseen by referring now to FIG. 2

FIG. 2 depicts the door assembly 114 as viewed from the interior of thepanelboard assembly wherein the hinges 15 are shown attached between thedoor 12 and the rabbet 14 within a hinge opening 1 formed within therabbet 14. A clearance gap 110 is provided between the door and the faceplate, and the handle opening 13 is formed within the door to allow forthe attachment of an operating handle and lock (not shown).

FIG. 3 shows the interior components prior to attachment within thepanelboard assembly. A main circuit breaker module 19 is comprised of apan 16 having L-shaped extensions 9 containing a plurality of holes 18to facilitate attachment of the pan to the interior of the assembly. Aninsulating barrier 23 separated from the pan 16 by means of legs 24 isused to electrically isolate the circuit breaker connecting straps 21 bymeans of spaced insulating shields 138. Electrical connection is madebetween the bus bars 30 and the connecting straps 21 by means of threecopper straps 130 and terminal screws 22, although only one is shown forpurposes of clarity. A main circuit breaker 20 or a main terminal lug(not shown) is carried by the main circuit breaker module and a pair ofupright shield supports 17 are provided on each of the L-shapedextensions 9 at one end of the module to support a pair of shield rails44 at that end. A branch circuit breaker module 25 is shown to consistof a pair of opposing side rails 26 connected together by means of apair of crossbars 27 which support and attach to the busbars 30 by meansof bolts extending downward through the respective bolt recesses 29formed in the cross bars and the bus holes 35 which extend along each ofthe buses, as indicated. A pair of crossbar side rails 28 are formedwithin the crossbars to provide additional support strength. The base 32is supported both by the busbars as well as by the side rails and servesto support a number of branch circuit breakers 31 which are removablymounted on the circuit breaker support hooks 34 formed within the base32 and separated by insulators 33. The neutral connection module 36includes a neutral base 37 made of sheet metal which supports a pair ofshield supports 17 at one end to which the opposite end of the pair ofshield rails 44 are attached. The large number of holes 45 providedwithin the shield rails allows the shield supports 17 to be fastened atany desired location. The neutral connection module 36 further comprisesa pair of opposing angle supports 39 of an insulating material on whicha metal platform 38 is placed. A plurality of neutral connectors 42 aremounted at one side of the platform and a neutral lug 40 is fastened tothe platform proximate the neutral connectors by means of a screw 41.The main circuit breaker module 19, branch circuit breaker module 25,and neutral connection module 36 are mechanically interconnected byoverlaying an end portion of the branch circuit breaker module siderails 26 on an end portion of the main circuit breaker module side railL-shaped extensions 9 and inserting at least two bolts on each side ofthe modules through the corresponding screw holes 18 and by overlayingan opposite end portion of the branch breaker module side rails 26 on anend portion of the neutral connection module side rails 131 andinserting at least two bolts on each side of the module through thecorresponding screw holes 18. The variability in the length of theindividual side rails for each individual module is an important featureof the instant invention. Earlier panelboard side rail lengthconfigurations generally fixed the panelboard interior dimensions andthereby limited the flexibility of the design. The arrangement of eachindividual pair of side rails for each individual module now allows alarge amount of flexibility within a fixed panelboard length. Eachmodule now is assigned one of the aforementioned functions, such as mainbreaker or branch breaker support for example, and the individual modulelengths can be varied by simply adjusting the length of the respectiveside rails. Electrical connection is made with the neutral connectionmodule by means of a plurality of neutral terminals 43 while electricalconnection between the neutral connectors 42, neutral lug 40 and neutralterminals 43 is made by means of the metal platform 38. The main andbranch circuit breaker modules are electrically interconnected byattaching the ends of the busbars 30 on the branch circuit breakermodule 25 to the circuit breaker connection straps 21 by means of theterminal screws 22 and copper straps 130 as described earlier. Theneutral connection module 36 is then abutted against the opposite end ofthe branch circuit breaker module 25. Once the individual modules areinterconnected and the pair of shield rails 44 are attached, thesubassembly is then arranged within the bottom pan 8 which consists ofthe opposing sidewalls 6 and the opposing end walls 5. A plurality ofmounting holes 7 are arranged on the bottom of the bottom pan 8 tofacilitate attachment within the field before the subassembly isinserted therein. A main circuit breaker shield 46 having a handleopening 47 for providing operative access to the main circuit breakerand a top shield 139 are supported between the shield rails 44 alongwith a branch breaker shield 48 which contains a shield shelf 4 alongboth sides of the shield and a pair of breaker access opening 49 throughwhich the top of the branch breakers 31 extend. A neutral shield 140 isalso supported between the same shield rails to completely shield theinterior assembly.

When a larger rated branch circuit breaker is to be used within thebranch circuit breaker module 25, the branch strap adapter 53 shown inFIG. 4 is used in place of the base 32 depicted earlier in FIGS. 1 and3. The branch strap adapter is indicated in phantom in FIG. 1 to showits arrangement within the interior of the panelboard assembly 10. Thebranch strap adapter consists of a cover 57 and a base 54 both made ofNoryl. The cover has a tube 63 integrally formed therein with an opening64 defined for receiving a sleeve 65 arranged at one end of the branchbreaker 31. Electrical connection is made between the branch breaker andone of the power buses 30 by fastening the captive screws 66 whichextend through the circuit breaker terminal straps 67, sleeve 65 andtube 63 to a hole 69 tapped within the branch strap 68. A threaded bolt70 is then inserted through the oblong hole 71 within the cover 57, andthrough the oblong hole 116 within an offset 115 formed at one end ofthe branch strap 68, where it is securely fastened to one of the powerbuses 30 within the bus hole 35 through the opening 129 formed in thebottom 113. Although only one branch strap adapter 53 is shown, thereare three such adapters employed, one for each of the three power buses30. When the branch circuit breaker is to be connected with theappropriate power bus 30 by means of the branch strap adapter 53, thecover 57 is first attached to the base 54 by fitting the edges of thecover within the linear passage 59, 60 defined between the outer wallsof the base and the inner formed rectangle 58 as shown. Upon insertionof the edges of the cover 57 within the linear passage, four protrusions62 formed on the outside of the edges of the cover become captured byfour corresponding slots 61 formed in the sides of the base 54. Thebottom 113 of the base 54 insulates the branch strap 68 from the otherbusbars which are not connected with the branch strap while providingaccess to one of the underlying bus bars 30 by means of the opening 129.A pair of unique busbar locating holes 117, extending through the branchstrap 68, and posts 118, formed on the bottom 113, ensure the correctlineup between the circuit breaker captive screw 66 and the hole 69within the branch strap 68 as well as between the slotted hole 116within the branch strap and the underlying busbar hole 35. A circuitbreaker support bracket 72 is attached to the base 54 by means of ascrew 76 and a screw hole 121 formed in the base. Attachment between thebranch breaker and the support bracket is made by means of a long screw73 which extends through the circuit breaker mounting hole 74 and a hole75 tapped within the support bracket 72. The assembled branch strapadapter 53 is attached to the side rails 26 by means of a pair of clamps50 at each end of the adapter which attach to the side rails by means ofbolts 51 and engage the recessed ends 55, 56 of the base by means ofhooks 52.

The operation of the branch strap locating holes 117 and branch straplocating posts 118 is best seen by referring now to FIG. 4A. The branchstrap 68 has either a narrow branch strap locating hole 117 or a widebranch strap locating hole 117' for positioning the branch strap withinthe branch strap adaptor base 54. The branch strap locating post 118seats the bottom of the narrow branch strap locating hole 117 on anarrow shoulder 119 as indicated in solid lines and seats the bottom ofthe wide branch strap locating hole 117' on a wide shoulder 120 asindicated in phantom. The linear passages 59, 60 are seen to extendalong both sides of the base 54 as indicated, and a hallow cylinder 126integrally formed within the bottom 113 of the base 54 is locatedbetween the branch strap locating posts 118. The purpose of the cylinder126, which is closed at the bottom as indicated at 127, is to allow forthe clearance of the bottom shank of the circuit breaker captive screw66 and to insulate the screw from the interior of the panelboardassembly.

Electrical connection between the busbars 30 with other electricalcomponents is made by means of the anti-turn connector 80 shown in FIG.5 which is first connected to the busbar 30 by means of a pair of screws91 passing through a pair of screw holes 90 formed within the connectorto a corresponding pair of screw holes 35 formed within the busbar. Abolt 85 having a hex head 84 and a formed washer 86 fixedly attached tothe head is inserted within a hexagonal slot 82 formed within a recess83 within the connector. The bolt is retained from passing through thehex slot by the engagement of the formed washer 86 within the recess 83.The busbar 30 is positioned such that the bolt 85 extends through thebusbar hole 35 and through a corresponding hole 87 formed within a step88 extending from the wire terminal lug 77. The hex nut 89 isthreadingly attached to the bolt 85 and a conductor (not shown) isinserted within the opening 78 defined within the wire terminal lugbefore the screw 79 is employed to fasten the conductor within the lug.

In some lighting power distribution circuits, the main circuit breakeris not used and the branch circuit breaker then connects with the powercircuit by means of three wire terminal lugs 77 as shown in both FIGS. 5and 10. Although three phase power circuits, which require three wireterminal lugs are disclosed, this is by way of example only. It is wellunderstood that in single phase power circuits, only two power buses arerequired and only two such wire terminal lugs would be emloyed. Theneutral connection module is not generally used with this circuitarrangement and a split neutral assembly module 132 is used in itsplace. The branch circuit breaker module 25 shown in FIG. 10 is similarto that depicted in FIG. 3 and like reference numerals will be employedfor similar components. The branch circuit breakers 31 are mounted on abase 32 and the busbars 30 are attached to the crossbars with side rails26 running parallel to the bus bars. Instead of connecting the bus barsto a main breaker, three wire terminal lugs 77 are connected with themain conductor (not shown) and with the bus bars 30 in the mannerdepicted in FIG. 5. The ends of the bus bars are arranged between thelug connectors and corresponding anti-turn connectors 80 and areattached to the anti-turn connectors by means of bolts 91 which extendthrough bolt holes 90 on the anti-turn connector and are engaged withinbolt holes 35 within the bus bars. The anti-turn connector 80 isconnected with both the bus bars 30 and the wire terminal lugs by meansof the bolt 85 and the hex nut 89 as described earlier. Referring againto FIG. 10, only one wire terminal lug 77 is indicated beforeattachment, with the other two lugs and anti-turn connectors alreadyattached. Once the wire terminal lugs are attached to the branch circuitbreaker module, the split neutral module is attached by placing aportion of the ends of the branch circuit breaker module side rails 26over a portion of the split neutral module side rails and joining themodules by means of at least two bolts through the respective side railbolt holes 18. When the modules are thus fastened together, the wireterminal lugs sit within the insulating barrier 23 and are insulatedfrom each other by means of the insulating shields 138 and from the pan16 by means of the legs 24. Neutral connections are made with the splitneutral assembly module 132 by means of the split neutral assembly 133which basically consists of a pair of insulating terminal bases 134joined by means of a connecting strap 137. Individual circuitconnections are made by means of a plurality of terminal connectors 135arranged on both of the terminal bases. Once the two modules areattached together, a modified main breaker shield similar to that shownin FIG. 3, without the handle opening 47, is attached by means of theshield rails 44 and shield supports 17 to the split neutral assemblymodule 132. The branch breaker shield 48, also shown in FIG. 3, isconnected to the branch circuit breaker module 25 by means of the shieldrail and shield supports to complete the assembly.

The attachment between the side rails 26, and the bottom pan 8 is madeby means of a plurality of bolts 100, 101 and angulated mountingbrackets 92 best seen by referring to FIGS. 3, 6 and 7. The angulatedmounting bracket 92 is shown in FIG. 6 to comprise a top step 94 and abottom step 95 offset in opposite directions from a vertical riser 93.The bracket is formed from a single piece of metal and a keyhole-shapedslot 98 is formed in the top step along with several holes 96. A similarkeyhole-shaped slot 99 is formed in the bottom step along with aplurality of holes 97. The keyhole-shaped top and bottom slots comprisedual diameter openings with the smaller diameter of one of the slotsfacing in an opposite direction from the other slot. This allows theangulated mounting bracket to be used in any orientation without havingto use four separate mounting brackets oriented in four separateddirections since it is desirable to provide the dual diameter slotconfiguration for ease in attachment of the bolt 101 indicated in FIG. 7for attachment within a screw hole 7 arranged within the bottom pan 8.The provision of the angulated mounting brackets 92 assure that thebases 32 are provided with sufficient support and that the cross bars 27are firmly supported within the panelboard assembly. Further support isprovided to the cross bars 27 by means of a plurality of ribs 122 formedduring the molding process. Prior art side rails were fixedly attachedto the bottom on only the ends of the side rails since the side raillength was a constant dimension. The provision of several mountingbrackets having side rail receiving holes 96, 97 and bottom panreceiving keyhole shaped slots 98, 99 now allows the module side railsto be attached at any desired location.

FIG. 8A shows a plurality of branch breakers 31 attached within thepanelboard assembly and each containing a circuit marker 102 containingidentifying indicia 103 in the form of numbers identifying eachparticular branch breaker with a particular circuit. After the circuitbreakers are connected either by means of a base 32 such a describedearlier with reference to FIG. 3, or by means of the branch strapadapter 53 described earlier with reference to FIG. 4, the branchbreaker shield 48 best seen in FIG. 3 is placed over the breakers bymounting the shield platforms 128 on the shield rails 44 which werepreviously attached to the assembly by means of shield supports 17. Thecircuit markers 102 are attached to the shield shelf 4 prior to placingthe shield over the branch breakers. The circuit marker 102 as detailedin FIGS. 8B and 8C consists of a U-shaped clip configuration made of adurable plastic material and defining a bight portion 123 with a pair oflegs 124, 125 formed such that the legs toe in towards each other tofirmly hold the circuit marker to the shield shelf 4. To prevent thecircuit markers from sliding along the shelf, a plurality of dimples 105are formed along the shelf extent such that a downward protrusion 106best seen in FIG. 8B prevents each of the circuit markers 102 frommoving along the shelf. A matte surface 104 is formed on the circuitmarker by abrasion or otherwise roughening the plastic surface so that aball point pen or pencil can be used to write the description of theappliances or lighting fixtures which are protected by the indicatedbranch breaker.

The integrally formed hinges 15 shown attached to the inner surface ofboth the face plate 11 and the door 12 are attached to the door and faceplate by the assembly depicted in FIG. 9. The door 12 is initially cutfrom a single sheet of steel defining a clearance gap 110 between theface plate 11 and the door 12 as indicated. The hinge 15 is formed froma single sheet of steel and defines a formed circular end 109 and anL-shaped end 111 as indicated. The flat portion 111A of the L-shaped endis robotically welded to the door 12 and a pin 108 is inserted withinthe formed circular end 109. A rabbet 14 formed from a single steelplate bent at right angles to provide a telescoping extension 2 alongits entire length is used to hold the hinge 15 between the face plateand the door. The rabbet has a hinge opening 1 cut in the vicinity ofthe hinges proximate the top and bottom of the door and a pair of formedsemi-circular protrusions 107, which correspond to and capture the pins108, when the rabbet is robotically spot-welded to the face plate 11 andthe hinge 15 protrudes upwards through the hinge opening 1. When therabbet is welded to the face plate, the door can freely open by theclearance provided the hinge through the hinge opening 1 and pins 108can rotate within the formed circular protrusions 107. It is noted thatwith the door 12 both in its open and closed positions, the formed hinge15 is completely inaccessible from the front surface of the panelboardassembly.

A review of the drawing figures indicates that all the installment stepsfor the panelboard assembly components can be made in a "downward"motion which is intended for purposes of automated assembly. Theinterrelationship between the component parts is such that roboticinstallation of the components can be made as the parts proceed along aconveyor with each of the components arrayed along the conveyor for bothinstallation and testing at each robot position.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:
 1. A circuit breaker panelboard assemblycomprising:closure means housing at least one main circuit breaker andat least one branch circuit breaker; access means movably arranged onsaid closure means providing access to said main and said branch circuitbreaker from outside of said closure; mounting means within said closuremeans supporting said branch circuit breaker and providing electricalconnection between said branch circuit breaker and electrical bus barswithin said closure means connectable with an external circuit; andshield means intermediate said access means and said main and branchcircuit breakers preventing contact with electrical terminals on saidmain and branch circuit breakers; said mounting means comprising anadapter member having an insulative cover and an insulative base, saidadaptor cover having first means integrally formed therein providingaccess to means electrically connecting said branch circuit breaker witha branch strap within said adapter base.
 2. The circuit breakerpanelboard assembly of claim 1 further including second means integrallyformed on said adapter cover providing access to means electricallyconnecting said branch circuit breaker with one of said bus bars.
 3. Thecircuit breaker panelboard assembly of claim 1 wherein said adaptercover includes protrusions and said adapter base includes correspondingslots receiving said protrusions and holding said adapter cover fixedlyto said adapter base.
 4. The circuit breaker panelboard assembly ofclaim 3 further including at least one branch strap locating pinintegrally formed within a bottom surface of said adapter base.
 5. Thecircuit breaker panelboard assembly of claim 1 further including ahollow cylinder integrally formed within said bottom surface andextending external to said adapter base.
 6. The circuit breakerpanelboard assembly of claim 4 wherein said locating pin has first andsecond diameters seating first and second sized holes through saidbranch strap.